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(No Model.) 0. S. PLATT 8v J. M. ORPORD.

ELECTRIC SWITCH. No. 427,521. Patented May 6, 1890.

IIIII lllll lllllll Illllll ulllll Illllll UNITED STATES PATENT Ormea.

OCRON S. vPLATT AND .IO'IIN M. ORFORD, OF BRIDGEPORT, CONNECTICUT; SAIDORFORD ASSIGNOR TO SAID PLATT.

ELECTRIC SWITCH.

SPECIFICATION forming part Of Letters Patent N0. 427,521, dated May 6,1890.

Application filed October Si 1889. Serial No. 326,313. (No model.)

To all whom, t may concern,.-

Be it known that we, OcRoN S. PLA'rr and JOHN M. ORFORD, citizens of theUnited States, residing at Bridgeport, in the county of Fairfield and'Stat-e of Connecticut, have invented certain new and usefulImprovements in Electric Switches; and we do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and use the same.

Our invention relates to certain new and useful improvements in electricswitches, and has for its object to provide a device of this descriptionwhich shall be simple in construction and inexpensive to manufacture, inwhich the handle may be turned in either direction to operate theswitch, and in which the making and breaking of contact, andparticularly the latter, shall be effected with great quick-v ness.Furthermore, our invention relates to a novel device for insuring closeand efticient contact with the terminals, which shall be constantlyoperative and not liable to deteriorate; and with these ends in view ourinvention consists in the construction and combination of elementshereinafter fully set forth,and then recited in the claims, andparticularly in the arrangement of parts whereby the contact-bar iscam-actuated in one di reetion and spring-actuated in the other.

In order that those skilled in the art to which our invention appertainsmay fully understand how to make and use our improvement, we willdescribe thesame in detail, reference being had to the accompanyingdrawings, which form a part of this specification, and in which- Figurel is an elevation showing the switch closed, the inclosing-cap beingsectioned and part of the base broken away; Fig. 2, a longitudinalvertical section showing the switch open; Fig. 3, a plan view, partly insection, showing the paris in their closed position; Fig. 4, a detailtransverse vertical section showing the parts in their closed position;Fig. 5, a detail end elevation of the bar and terminals in their closedposition; Fig. 6, a detail plan view of the contact-bar with contactsremoved, the legs of the housing being shown in section; Fig. 7 a detailtransverse section through the wedge, showing the connection between itand the operati11g-s1indle.

The drawings represent our invention as embodied in a double-poleswitch; but it is obvious that it is equally applicable to an ordinarysingle-pole switch.

Like numerals refer to the same parts in all the figures of thedrawings.

lis a base-block, which maybe of wood, porcelain, or other suitablematerial, and upon whose surface are secured the terminals 2, to whichthe circuit-wires are adapted to be attached in any usual or suitablemanner. The opposed faces of these terminals are preferably inclined, asseen at the detail, Fig. 5, so that the space between them may beconvergent from the top of the terminals to the surface of the block.The terminals are properly insulated from each other.

3 is a housing mounted on the block at about the center thereof, saidhousing being constructed, preferably, with four posts or legs, so as toleave it open both at its ends and sides. Vithin this housing, whichforms a bearing in which it may slide vertically, is arranged thecontact-bar 4t, having in its top a recess 5, V-shaped in cross-section,and substantially vertical as to its end walls.

(i is a spindle having a handle 7 at its upper end. Said spindle passesvertically through the top of the housing, and immediately below the topwall of said housing it carries a wedge-shaped cam S, conformed incross-section to the shape of the recess in the contactbar.

The connection between the spindle and the cam will be readilyunderstood by reference to the small detail, Fig. '7, which shows thecam as pierced vertically for the passage of the spindle and saidspindle as having a transverse opening 9, tapered from either end to thecenter thereof, and a pin l0 passed lengthwise through the cam and thedoublytapered opening. The purpose of this method of connection willpresently appear. The

lower end of the spindle passes downward into a recessll in thebase-block, and has a bearing in the bottom of the latter, and a spring12 is coiled loosely about the spindle,

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and has end bearings respectively against the bottom of the recess andthe lower surface of the contact-bar.

13 is a washer secured to the spindle.

14 are insulating-washers slightly larger in diameter than the centralportion of the contact-bar, and secured upon the ends thereof inside thecaps l5, also of insulating material. i

1G are ferrules, preferably of conducting material, surrounding the caps15, and to these are secured, as by screws, a series of thin iiexibleplates broadly U-shaped, as seen at the detail, Fig. 5. Heretofore suchplates for contact purposes have been employed; but when made of purecopper, so as to be of high conductivity, they have been found of lowresilience, and consequently have been liable to retain their bent shapeand so fail to give the strong and perfect contact required. Conversely,when made of metal of high spring quality they are deficient inconductivity and furnish a section in the circuit having relatively highresistance.

` In order that the requisites of conductivity and resilience may bothbe present, we employ plates formed of different metals, and preferablyarrange these contacts with an inner plate of German silver 17, designedto furnish the required spring quality, and an outer plate or plates 18of pure copper for its high conductivity. Thus the contacts are ofnearly or quite as high conducting power as if ofpure copper, and theinner plate or plates of spring metal give a resilience substantiallysuch as would be derived from contacts made entirely of such metal. Anynumber or arrangement of such plates, provided they be of metalsdiffering in resilience, we deem to be within the scope of ourinvention; but German silver is preferred for the inside plates, sinceits spring quality is but slightly affected by heat.

19 is a plate-spring secured to the side of the housingand bearing withits end against the extremity of the cam when the latter is intheposition shown at Figs. 1 and 3. In place of this spring, or asauxiliary thereto, we may provide shallow notches 20 on the top of thecontact-bar, and in which the sharp edge of the cam may rest when theswitch is closed. The object of the notch and spring, or either of them,is to hold the cam in its position transverse to the bar as againstreturning to the recess in the bar, either by jar or by means other thanthe turning of the spindle. Said notch and spring or either of them alsoserve to indicate to the person operating the switch when the contact iscomplete.

In the operation of our invention, when the switch is open thewedge-shaped cam rests in the V-shaped recess in the contact-bar, andthe contact-plates are above the space between the terminals and out ofcontact with In closing the switch the spindle is turned by means of thehandle, whereupon the cam drives the contact-bar downward and rides overthe inner faces of the recess until its edge rests transversely on thetop of the bar and in the notches, or with the spring bearing against`its end, or both, according to the construction of the switch. Thisdownward movement of the bar is effected against the action of thespiral spring, and causes the plates on the ends of said bar to beforced into close contact with the terminals, which contact, the springquality of the resilient plates helps to make and preserve. When thehandle is turned with reasonable rapidity, the closing of the circuit iseffected very quickly. In opening the circuit the spindle is turned bythe handle until the ends of the cam strike the edges of the inclinedrecess in the bar, whereupon the upward pressure of the spring jumps thebar out of contact very quickly and turns the cam so that it seats inthe recess. It is to prevent any delay in this operation that the wedgeand spindle are connected in the manner shown at Fig. 7, which method ofconnection admits of a slight rotary movement being imparted to the cam,so that it may seat in the recess irrespective of the continuance of theturning movement of the handle beyond the point necessary to carry thepoints of the cam to the top of the inclined surfaces of the recess.

In this our invention we do not wish to be confined to the precisedetails of construction herein shown and described, since many minorchanges not involving the exercise of invention may be made thereinwithout departing from the spirit and aim of our invention, as set forthin the claims hereunto annexed.

IVe claim- 1. In an electric double-pole switch, the

combination, with the base and the two pairsv of insulated terminals, ofa housing open at its ends and sides and mounted on the base between theterminals, a contact-bararranged within said housing and having side andend bearings against it, a Vshaped recess in the top surface of the bar,contact-plates mounted upon the ends of the bar and adapted to join theterminals, the rotary spindle, the spring, the operating handle, and thecam adapted to the recess and loosely secured to the spindle,substantially as set forth.

2. In a double-pole switch,the combination with the base and the twopairs of terminals, of the transversely-extended bar having upon itsends and insulated therefrom' the conducting-plates 17 1S, the housingsecured over said bar and forming a bearing for said bar as againstmovement either sidewise or in the direction of its length, the rotativeoperating-spindle, and the cam adapted to move with the spindle andcapable in addition of a limited movement independent of said spindleand about the latter as an axis, substantially as set forth.

3. In an electric switch, the combination, with the base and theterminals, of the contact-bar having contacts at its ends and hav- ICOIIO

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ing at its center transverse projections, the the broadly U-shapedplates 17 18, all arfour-legged housing set over said bar and ranged asdescribed, and for the purpose set -adapted to limit its movement bothlengthfortn. t

wise and sidewise, and means for imparting` In testimony whereof Weatiix onrsignatures 5 to said bar its appropriate vertical movement inpresence of two witnesses.

within the housing, substantially as set forth. Y o OCRON S. PLATT.

4C. In an electric switch, the combination, i JOHN M. ORFORD.

with the terminals, of the vertically-movable lVtnesses:

contact-bar having reduced extremities, the S. H. HUBBARD, Io Washers14, the caps 15, the ferrules 1G, and M. C. HINCHCLIFFE.

